I called XFX and they told me the 4" would be long enough to fit. The ones that XFX included with the cards are 2.75"/7cm. I measured it with a measuring tape last night and the tech from XFX was right, they ship 7cm bridges. I also measured the distance on the graphics cards and it came out to 3.6" from the bottom of the second GPU finger to the bottom of the first GPU finger.

This is also considering I have a Asus Maximus VI Hero board that has a PCIe1x slot inbetween each PCIe 16x lane.